418 BIOLOGY AND ITS MAKERS 
tinued, ‘and you can not form any idea of what I felt on 
receiving the news of the meeting on the 19th. In Geoffroy 
de Saint-Hilaire we have now a mighty ally for a long time 
to come. But I see also how great the sympathy of the 
French scientific world must be in this affair, for, in spite of 
the terrible political excitement, the meeting on the 19th 
was attended by a full house. The best of it is, however, 
that the synthetic treatment of nature, introduced into 
France by Geoffroy, can now no longer be stopped. This 
matter has now become public through the discussions in the 
Academy, carried on in the presence of a large audience; 
it can no longer be referred to secret committees, or be settled 
or suppressed behind closed doors.’ ” 
Influence of Lyell’s Principles of Geology.—But just as 
Cuvier was triumphing over Saint-Hilaire a work was being 
published in England which was destined to overthrow the 
position of Cuvier and to bring again a sufficient foundation 
for the basis of mutability of species. I refer to Lyell’s 
Principles of Geology, the influence of which has already 
been spoken of in Chapter XV. Lyell laid down the prin- 
ciple that we are to interpret occurrences in the past in the 
terms of what is occurring in the present. He demonstrated 
that observations upon the present show that the surface of 
the earth is undergoing gradually slow changes through the 
action of various agents, and he pointed out that we must 
view the occurrences in the past in the light of occurrences 
in the present. Once this was applied to animal forms it 
became evident that the observations upon animals and plants 
in the present must be applied to the life of the fossil series. 
These ideas, then, paved the way for the conception of 
changes in nature as being one continuous series. 
H. Spencer.—In 1852 came the publication of Herbert 
Spencer in the Leader, in which he came very near antici- 
pating the doctrine of natural selection. He advanced the 
